The present invention relates to a conversational-type natural language analysis apparatus that is applicable to a machine translation apparatus, a natural language conversational system and the like.
The "National Language Translation Support System" disclosed in Japanese Laid Open Patent Application No. 140582-1984 relates to a machine translation system that supplies information to support the translation process prior to the performance of syntax analysis. This system uses information that is provided, to translate input sentences. In such a machine translation system, the information that the user has to provide differs according to the input sentence. Accordingly, the user must understand what type of information has to be provided and then select it. This creates a large load for the user. Such a type of machine translation system is termed a "pre-edit" type of system.
The "Text Display & Correction Apparatus in a Machine Translation System" disclosed in Japanese Laid Open Patent Application No. 101365-1983 relates to a machine translation system in which the sentence is first generated and the input original sentence and the corresponding translated sentence are compared by the user in predetermined units and the user corrects the translated sentence in those units.
In addition, in the "Machine Translation System" disclosed in Japanese Laid open Patent Application No. 271060-1987, the translated sentence corresponding to the input original sentence is first generated and if the user requires a different translated sentence, re-translation is performed by using the one candidate from a set of candidate syntactical relations that could be used and which has the highest possibility (evaluation score) of being correct. Furthermore, in the above described Japanese Laid Open Patent Application No. 271060-1987 is also disclosed a "Machine Translation System." In this machine translation system, the translated sentence corresponding to the input original sentence is first provided and then if the user judges that there is an error in that translated sentence, the user specifies the modifier clause of the input original sentence and candidate modified clauses are provide. Then, the user selects and specifies the candidate modified clause that is the most suitable from the list of modified clauses provided for the user. This system performs retranslation using the modified clause that was specified as corresponding to the modifier clause of the input original sentence. These machine translation systems are termed "post-edit" type systems.
In such "post-edit" type systems, it is difficult to perform complete automatic and analysis using current technology. Accordingly, the user must either make judgments as to whether the translated sentence provided by the system is correct or incorrect, and perform the correction of the translated sentence if it is wrong. This work represents a large workload for the user.
The "Correction Method" disclosed in Japanese Laid Open Patent Application No. 18073-1986 displays an analysis tree as the results of analyzing the input original sentence and the user then uses basic commands to correct the analysis tree that is displayed.
In addition, in the "Control Method for Syntactical Analysis Results Display & Correction" disclosed in Japanese Laid Open Patent application No. 278970-1986, the system expresses and analysis tree in a small amount of space as the result of analysis of the input original sentence and then the system receives corrections that the user makes to that analysis tree. These types of systems are termed "mid-edit" systems.
In such "mid-edit" systems, the meaning of the analysis results such as analysis tree and the like is difficult to understand for a general user who does not understand the mechanics of the operation. In addition, the user must not only the correction of error analysis but must also make judgments as to the correctness or incorrectness of correct analysis results. This represents a large burden for the user. The "Human Intervention Method for Causes of indeterminable Meaning in Machine Translation" disclosed in Japanese Laid Open Patent Application No. 132270-1082 relates to a machine translation system. In this machine translation system, syntactical structures for which the meaning cannot be determined are displayed and information is presented to the user in order to determine the meaning, and the given information is used for translation. Such a type of machine translation system is termed a "conversational-type" machine translation system. In the case where many sentences have to be translated, the number of meanings cannot be determined becomes considerably large and providing the user with the information required to determine the meaning is unrealistic in practical terms. Accordingly, it is desirable that the extent of the indeterminable meaning be considered and that the syntactical structure that requires information from the user be selected.
In addition, the "Translation Method" disclosed in Japanese Laid Open Patent Application No. 80362-1986 and Japanese Laid Open Patent Application No. 90269-1986 related to machine translation systems. In these machine translation systems, the syntax of the input original sentence is performed and the relationships for the configuring elements that form the analysis results are presented to the user. Then, the user checks these analysis results, and when the user judges a relationship to be incorrect, the user then specifies a correct relationship and the system performs re-translation in accordance with that specification.
When many sentences have to be translated, the number of relationships for the configuring elements becomes large to the extent that it is no longer realistic in practical terms for the user to make judgments about the correctness or incorrectness for all such relationships. Accordingly, it is desirable that the number of judgments that the user has to make be limited to only vague relationships and unclear portions and the like.
In addition, the "Translation Support Apparatus" disclosed in Japanese Laid Open Patent Application No. 290976-1987 also relates to a machine translation system. When a vague or unclear portion is generated in the process where the input original sentence is analyzed, question and response is performed for between the user and the system and the information obtained is used to progress with the analysis. When this is done, the load on the user is lessened if the user is questioned in an easy-to-understand manner and in accordance with type and contents of a vague or unclear portion, so that the user can respond promptly.
When many sentences have to be translated, the number of these vague or unclear portions increases considerably and it is a great load on the user to gave to make judgments for all of these. Accordingly, it is desirable that the questioning be performed for those items for which there is a large degree of vagueness or lack of clarity.
In addition, the "Vague Modifier Relationship Detection Method" disclosed in Japanese Laid Open Patent Application No. 98072-1988" relates to a natural language conversational-type system. In this natural language conversational-type system, analysis is performed for the sentence in question, vague modifier relationships are detected, and all possible modifier relationships are presented to the user who then makes a selection. Then, the modifier relationship that is selected by the user, is used to perform a correct analysis. The vague modifier relationship is detected by the use of a vague modifier patterns that are stored in the system.
When there are a large number of sentences to be translated, the number of these vague modifier relationships becomes considerably large and it becomes a large load for the user to make judgments for all of them. In addition, there are many types of vagueness that a sentence can have and it is difficult to have patterns for all types.
The technology for the analysis of language is still not mature and it is difficult to have complete and automatic analysis. There are basically two methods for the solution of this problem. One of these methods is to (1) limit the number of objects of analysis and the second method is to (2) limit the degree of automation of analysis. The present invention relates to the latter method. There are four methods for limiting the degree of automation. They are as follows, for the respective types of translation method.
(2)-1 Pre-edit type: Having the user perform prior edit for the original sentences to make them into a form in which they can analyzed by the system. PA1 (2)-2 Post-edit type: In a process that uses machine translation and language analysis results, having the user correct the final results of the system for processing. PA1 (2)-3 Mid-edit type: Having the user perform correction of the language results of the system themselves. PA1 (2)-4 Conversational-type: Having the user cooperate and perform the analysis.
The present invention relates to this fourth method.
The problem with the method (1) is that it is difficult to confirm whether the original that has to be analyzed is within the limits or not. The problems for (2)-1, (2)-2, (2)-3 are as described above but this problem does not apply to (2)-4. The problems with the conventional technology for (2)-4 have already been described but the common problem is that "the total number of portions that cannot be determined by the system becomes larger when many sentences have to be translated." It is unrealistic that user supports all of them.